The capability represents that qemu accepts the configuration of the
HPET timer via -machine hpet=on/off rather than the
soon-to-be-deprecated '-no-hpet' option.
The capability is detected from 'query-command-line-options' which
recently added the 'hpet' option.
Signed-off-by: Peter Krempa <pkrempa@redhat.com> Reviewed-by: Ján Tomko <jtomko@redhat.com> Reviewed-by: Thomas Huth <thuth@redhat.com>